Considering normal records have absolutley none [fire truck siren noise], I would consider it completly unlistenable, but if you deem it "not so bad", so be it.

Sure they do. Just at a much smaller scale.

My point is that you are dead wrong; they don't have any, not at any scale, none, not even in theory. But feel free to use strawman arguments and change the subject to "but the real question is... blah-blah-blah" as much as you'd like. I don't care nor will address any such red herrings.

To the needle, as it plays these impossible to properly track squares, the signal seems to be a signal which alternates between square waves to triangular waves, twice per 1.8 second rotation:

Is incorrect. The stylus is too large to see 600dpi squares and triangles (edit: ahh - except for the four times per revolution the stylus is aligned with the axis of the pinter) just as it is too large to see molecules of vinyl.

There's no red herring, there's no strawman.

I never denied their was aliasing caused by the coarseness of the printing...

... My point is that you are dead wrong; they don't have any, not at any scale, none, not even in theory. But feel free to use strawman arguments and change the subject to "but the real question is... blah-blah-blah" as much as you'd like. I don't care nor will address any such red herrings.

Wooo. Pot, kettle, black.

Real LPs may not have fire engine noises. They do have noise due to the size of the vinyl molecules. It sets the lower limit of the resolution that can be realised, just as the size of your eardrums sets the lowest limit on the resolution of your hearing. (If your ears were any more sensitive, you'd hear a constant noise from the air molecules bouncing off your eardrums.)

The following page by Jim Lesurf will give you an appreciation of the dimensions involved - what resolution would be required in a 3D printer to reach the resolution of a traditional LP.

I wouldn't advise this! The stylus isn't playing a smooth waveform, it is attempting to play a staircase textured groove wall. The constant bashing of the needle between steps is analogous (pardon the pun) to applying an improperly light, downward tracking force with a normal record, also very bad. Besides the distortion, it wears down the needle very quickly with all the side to side groove bashing going on!

That is amazing. I'm sure it's not too difficult to write a program to make an STL file, but getting access to a 3D printer that large and accurate is either hard, or expensive!

It's too hard and expensive now. As Mzil says, even state of the art printers are still too crude to print LPs as good as the traditional method. But it won't be that way for very long. Resolutions are increasing all the time and costs are coming down. Eventually it'll reach a point where the quality meets or exceeds traditional pressing. It'll reach the same point as CDRs have versus pressed CDs - printing will be cheaper than pressing for short runs. For LPs, this is a good thing - it'll become economic to produce a wider catalog of LPs for what is a relatively small market.